Beyond the symmetry limit, various methods have been implemented for the evaluation of baryon magnetic moments. An important selection of such methods can be found in Ref. [1]}. One of the earliest methods is chiral perturbation theory. Caldi and Pagels pointed out that nonanalytical corrections of orders \(\mathcal {O}(m_q^{1/2})\)  and \(\mathcal {O}(m_q \ln m_q)\)  in the perturbative series are calculable [2]}. They tackled the former and found them to be as large as the lowest-order values, which would indicate a breakdown of the perturbative expansion. It was not until the arrival of heavy baryon chiral perturbation theory first introduced by Jenkins and Manohar [3]}, [4]} that some aspects of the theory were properly understood. When the method was applied to the renormalization of the baryon axial current, chiral logarithmic corrections to the axial couplings in hyperon semileptonic decays were found to be as large as the lowest order values when only intermediate octet baryons were included in the loops [3]}. The inclusion of both octet and decuplet baryons in the loops reduced considerably the corrections with respect to the case with the inclusion of octet states alone [4]}. The cancellation pointed out phenomenologically in Refs. [3]}, [4]} was later proved in the context of the \(1/N_c\)  expansion of QCD in Refs. [9]}, [10]}, [11]}, [12]}, [13]}, where \(N_c\)  is the number of quark charges.
